Package gnu.jel
Class OP
java.lang.Object
gnu.jel.OP
A tree node, representing an operation.
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Field Summary
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionabstract void
Called to generate the code implementing this OP.abstract Object
eval()
Called to evaluate this node and all its sub-nodes.static boolean
isWidening
(int id1, Class<?> c1, int id2, Class<?> c2) Used to find out if the conversion t1->t2 is widening.static boolean
isWidening
(Class<?> c1, Class<?> c2) Used to find out if the conversion t1->t2 is widening.protected static Object
Narrows the value back to desired primitiva type.static final int
Identifies the primitive type of the given class.static final int
Identify the primitive type corresponding to the given reflection object.protected static Number
Makes widest possible representation of a value of Java primitive type.
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Field Details
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chi
Holds references to children of this node -
resID
public int resIDHolds type ID of the result of this OP -
resType
Holds type of the result of this OP -
specialTypes
Classes of the special types by ID.The frequently used types (those on which many operations are defined) are identified by an integer number. The advantage is the possibility to have almost completely table driven code generator.
So, the special types are only special in the fact that except of the reference to their class object they are also identified by an integer number.
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unwrapType
public static final byte[] unwrapTypeUnwraps the type ID.That is all special types which are references are translated into 8.
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Constructor Details
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OP
public OP()
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Method Details
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eval
Called to evaluate this node and all its sub-nodes.Upon success this node is to be replaced by the constant node holding the returned object.
- Returns:
- an object to which this node evaluates
- Throws:
Exception
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compile
Called to generate the code implementing this OP.- Parameters:
cf
- class file with a new open method to write the code into.
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typeID
Identifies the primitive type of the given class.- Parameters:
c
- class to identify.- Returns:
- id of the corresponding primitive type.
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typeIDObject
Identify the primitive type corresponding to the given reflection object.- Parameters:
o
- object to identify.- Returns:
- id of the corresponding primitive type.
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isWidening
Used to find out if the conversion t1->t2 is widening.- Parameters:
id1
- type ID to convert fromc1
- class to convert from (used if id1==8)id2
- type ID to convert toc2
- class to convert to (used if id2==8)- Returns:
- true if the given conversion is widening (can be done automatically)
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isWidening
Used to find out if the conversion t1->t2 is widening.- Parameters:
c1
- class to convert from (used if id1==8)c2
- class to convert to (used if id2==8)- Returns:
- true if the given conversion is widening (can be done automatically)
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widen
Makes widest possible representation of a value of Java primitive type.- Parameters:
o
- reflection object, containing value to represent.clsID
- ID of a type of this reflection object (to save lookup).- Returns:
- Number, representing the given value.
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narrow
Narrows the value back to desired primitiva type.- Parameters:
val
- reflection object, containing value to narrow.clsID
- ID of a type to narrow the given object into.- Returns:
- narrowed reflection object.
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